Consider these words, spoken by the head of criminality and detention at the UK Border Agency (UKBA), in response to allegations that the nine-year old son of an asylum seeker had been mistreated by UKBA staff:

Whenever we take decisions involving children, their welfare comes first and we will always seek to act in the best interests of the child. That's why we have transformed our children's policy, enshrining in law a commitment to protect youngsters and keep them safe from harm. Treating children with care and compassion is a priority for the UKBA.

Now compare those words with an account of the arrest and detention of that nine-year old along with his mother and elder brother. The family are fighting removal to Iran, where they fear persecution after police found copies of Salman Rushdie's novel The Satanic Verses at their home. The account was given by the boy himself, speaking through an interpreter:

I was taking a picture of my stuff for school. Suddenly I saw the officers from the kitchen window, and I said to Mum: 'They are coming to our home'. After that, they came through, about eight people I think, and they said: 'You are going somewhere that you have been before.' They meant detention. I understood that we had to go back to detention.

The boy, who cannot be named for legal reasons, is known as child M, and the arrest came in Manchester last month as he was preparing for school. He knew the visit meant detention because he had been there before, to Yarl's Wood immigration removal centre, where he and his family had been held for a month in 2008. Teachers at his school describe him as a bright, very likable boy, who was recovering from the physical and mental effects of his previous incarceration when the officers called again.

Back to Child M's account:

Then two of them brought me upstairs and told me to hurry and pack my stuff. I started to be terrified.

The boy was not to see his mother again for several hours. While he was upstairs, his mother fell ill and eventually the officers sent for an ambulance. The last time the boy had seen his father was when he was taken in an ambulance after a road accident in Iraq and subsequently died. "When they wanted to take my mum to ambulance I wanted to see her, but they didn't let me," said Child M.

In the absence of his mother and brother, who travelled to hospital with the sick woman, Child M was questioned about the whereabouts of his sister, who had been staying with friends. Their questions concerned him: "I still thought they wanted to go and arrest her and I was very worried."

Eventually, the boy was taken to the hospital, but not to see his mother. He was detained in a vehicle outside. He thinks it was for seven hours, the UKBA says it was just under three. In their response, the agency said Child M was "relaxed and comfortable throughout and provided with food and drink". The boy saw it differently:

After that, they keep me for seven hours in the van and they didn't even let me to come out for fresh air. Sometimes they asked me things and they talked to me, but I was frightened because they were so big, like a monster, and I wanted to run away from them. I have never been so lonely in my life, without my friends and family. I was scared of these strangers and wanted to cry, but I couldn't. Suddenly they brought my mum in a wheelchair and they took us to detention. I was so happy to see my mum and my brother again.

Remember the words of the UKBA? "Whenever we take decisions involving children, their welfare comes first and we will always seek to act in the best interests of the child". Was it in this child's best interest to keep him separated from his mother and brother for several hours? Or to question him about the whereabouts of his sister? Remember, this is a nine-year-old. The police would not be allowed to question a child of that age without an "appropriate adult" being present; in his case, two adults held dear to him had gone and he was alone with strangers.

Is it in the best interests of this, or any other child, to be held in custody; for the crime of being born to those who seek a safer life in this country? It happens to hundreds of children every year. It makes me sick and angry and ashamed of this United Kingdom, which mistreats such children in our name.

While researching this story, I tried to contact Phil Woolas, the borders and immigration minister. I was told by his constituency office that he was "having a family day". Good for him, families are important; but I wonder if the minister ever stops to consider the effect the policy and practice he endorses have on asylum seekers and their families? Professionals who know of Child M's ordeal are in no doubt: Sir Al Aynsley-Green, the children's commissioner for England said:

Children in these stressful circumstances should never be separated from their parents, but if there is an exceptional reason why a parent cannot be with their child, then that child should be looked after by a responsible adult who they can trust and relate to. Children should also not be interviewed alone by officials. Children in immigration removal centres have told me about the distress and anxiety they feel during the arrest process and while in detention, therefore any period of separation from loved ones will only make them feel much worse. When a child is deprived of his or her liberty, particular care must be taken to ensure that they are treated with humanity and respect.

Katy Rosario is a teacher at Child M's school and also the safeguarding officer, responsible for children's welfare. She said:

I am deeply concerned that a nine-year-old child was left with strangers for a number of hours while separated from his mother. As teachers, we would not be allowed to do that. The officers concerned should have contacted the school or social services.

The weasel words of UKBA are far removed from their deeds. The agency and its political masters ought to be ashamed of themselves and all right-thinking people should protest at their actions.